Trigger switch with lost motion connection

ABSTRACT

A trigger operated electrical control for an electrically powered device, such as for instance a portable electric motor driven tool, for controlling the application of electric energy from an energy source to the motor. The control includes a contact carrier which, upon actuation, controls the operation of the said electrical control. A finger actuated trigger member is mounted on the carrier for causing actuation of the same, and means are provided, coacting between the carrier and the trigger, for movably mounting said trigger to the carrier and for providing predetermined magnitude of pre-travel of the trigger relative to the contact carrier. By providing for such trigger pre-travel, the actuation of the control is accomplished only after the trigger has been first moved through its predetermined &#39;&#39;&#39;&#39;pre-travel&#39;&#39;&#39;&#39; distance whereafter said control may be safely, smoothly and precisely controlled upon squeezing of the trigger by the finger of the operator.

waited States Patent [191 Sahrbacker [4 1 Sept. 9, 1975 TRIGGER SWITCH WITH LOST MOTEON CONNECTION [75] Inventor: Edward V. Sahrbacker, Brecksville,

Ohio

[73] Assignee: Lucerne Products, Inc., Hudson,

Ohio

[22] Filed: Dec. 26, 1973 [21] Appl. No.: 427,930

[52] US. Cl 200/157; 200/153 V [51] int. Cl. ..H0lh 13/08; HOlh 3/48 [58] Field of Search 200/153 V, 157; 338/198,

Primary ExaminerRobert K. Schaffer Assistant ExaminerWilliarn J. Smith Altomey, Agent, or Firm-Baldwin, Egan, Walling & Fetzer [57] ABSTRACT A trigger operated electrical control for an electrically powered device, such as for instance a portable electric motor driven tool, for controlling the application of electric energy from an energy source to the motor. The control includes a contact carrier which, upon actuation, controls the operation of the said electrical control. A finger actuated trigger member is mounted on the carrier for causing actuation of the same, and

means are provided, coacting between the carrier and the trigger, for movably mounting said trigger to the carrier and for providing predetermined magnitude of pre-travel of the trigger relative to the contact carrier. By providing for such trigger pre-travel, the actuation of the control is accomplished only after the trigger has been first moved through its predetermined pretravel distance whereafter said control may be safely, smoothly and precisely controlled upon squeezing of the trigger by the finger of the operator.

5 Claims, 6 Drawing Figures [56] References Cited UNITED STATES PATENTS 3,389,365 6/1968 Matthews ct al. 338/179 X 3,485,975 12/1969 Long 200/153 V 3,673,365 6/1972 Schadow.... 200/153 V X 3,766,348 10/1973 Johnson 200/157 3,790,730 2/1974 Wyland i 200/153 V a A, an n an a Q Q: m

PATENTED SEP 9 TRIGGER SWITCH WITH LOST MOTION CONNECTION" Y r This invention rclatcsin general to electrical tools. power appliances or the like, such as for instance, an

' electric drill. and more particularly to an electrical control for turning the motor of the tool or appliance on and off upon movement ofa manually operable trigger.

BACKGROUND OF THE INVENTION Trigger controlledpower operated tools. appliances or the like are well known in the art, some of which also include arrangements for variably controlling the speed ofthe motorof the tool by mov'ement of the trigger mechanism. One patent relating to such arrangememt is'U.S Pat. No. 35261973 dated Oct. 27, I970 in the name'of B. H. Matthews et al.,'and entitled Switch and Speed Control for Electric Motor." Another switch structure for ON-OFF control of a portable electric tool is shown inU.S. Pat. RE. 26,267, also in the name of B. H Matthews. Such prior art speed controls and switch devices generally include a contact. carrier which is adapted to actuate the electrical control or device upon movement of the carrier, with the carrier having atrigger element adapted to be squeezed by the finger of the operator to cause actuation of the control. In each structure of the prior art, as illustrated in the aforesaid patents, the actuator ofthe trigger element (28 or 16) actuates or turns on the .clectrical control or switch device. 4

SUMMARYYQ'OFTHE INVENTION The present invention, provides anelectrical control or switch device for, usc with portable hand, tools,

power applicances or the like, and which includes a carrier member for actuating the control or device upon movement thereofto an -onv position. and a separate trigger movably attached to: the said carrier and which provides for. predetermined I-pre-travel" movement of the trigger. by. the operator priortto the actuation of the contact carrier bysaid trigger whereby .said" control or device-is actuated-onlyafter the triggerthas moved throughitsf prmtravcl"distance, thus providing a safe-on" control or switch device; n I

Accordingly, an object of the invention is to provide a novel electricalcontrol'or, switch devicezwhich incor- I.

trical control or switch device which includes a contact carrier for actuating the'con'tact or switch device up'on movement of the carrier. and a separate trigger member coacting with the'carrier for actuating the carrier upon squcezing'ofthc tfigger member by the finger of an operator, and wherein means are provided coacting between the trigger and thecarrier to provide 'predetermined magnitude of pre-trai/el of the trigger prior to actuation of the carrier by the trigger.

Another object ofthei'nve ntion' to provide a control or switch device assembly as aforcdescribed and wherein the trigger is automatically returned to its foff position" upon its release by the operator.

Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings wherein;

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary, side elevational view of a portable electric tool embodyingthe control or switch device of the present invention, various pre-travel positions for the trigger with respect to the carrier thereof being shown in phantom lines;

FIG. 2 is a front elevational view of the trigger member of the control assembly;

FIG. 3 is a sectional view taken along the plane of the line 3 3 of FIG. 2 looking in the direction of the arrows;

FIG. 4 is a front end elevational view of the carrier member of the trigger-operated control;

FIG. 5 is a side elevational view of the carrier member of FIG. 4; and I FIG. 6 is a partial sectional view of a second embodiment of trigger and carrier assembly of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT As illustrated in the drawings and described herein I the present invention is shown adapted for use with the speed control of the type described in the Matthews ct al.'U.S. Pat. No. 3,526,973; however, as will be hereinafter apparent, the present invention is equally applicable'to the switch structure described in the Matthews patent, RE. 26,267.

Referring now again to the drawings, reference number l0 identifies a part of the tool housing of a powered hand tool with which the present invention may be expeditiously incorporated. As more fully described in the Matthews et al. US. Pat. No. 3,526,973 the housing shown herein is that part of the tool that is known as the pistol grip part of the housing and in which is carried trigger-control assembly 12 adapted to variably control the operation of the electrical power unit such as an electric motor (not shown) of the tool.

The trigger-control 12 may include a housing 14 in which is disposed the electrical contacts and associated circuit components for connection to the tool motor.

The control 12 includes a contact carrier 16 mounted for reciprocal movement relative to the control housing 14, and carries electrical contacts which are brought into and out of electrical engagement with the housing contacts and associated circuitry for causing actuation of the said control. Spring 18 may be provided in housing 14, coacting with the contact carrier for urging the :latter to off position.

v Mounted on the outer end of the carrier 16 is a separate trigger member 20 thus positioned to be squeezed by the finger of the operator, to cause movable actuation ofthe contact carrier 16 and thereby to actuate the electrical contacts of the control or switch device effective to turn the control device to its on" position.

Trigger 20 includes a longitudinally extending passageway 22 (FIGS. 2 and 3) which opens to the rear edge of the trigger 20 and which receives therein the forward portion of carrier 16. Side walls 24 of trigger 20, which define passageway 22, embody therein longitudinally extending slots or recesses 26 which are adapted to guidingly receive therein wings 28 formed the trigger 20 relative to the carrier 16 as will be hereinafter described.

The forward end of carrier 16 is provided with an upwardly extending post 30 (FIG. which abuts against a pin 32 (FIG. 1 extending through opening 34 formed in the upper ledge 36 of the trigger 20. As particularly shown in FIG. 1 pin 32 depends downwardly through opening 34 and abuts against the post 30 by reason of the spring 38, coacting between the front wall 40 of trigger and a shoulder 42 formed in recess 44 opening onto the frontal end of carrier 16 which urges said trigger to its fully extended position on the carrier.

A projection 52 may be provided coacting with the spring 38 to locate and position said spring relative to the trigger. Moreover, the surface 52 of the trigger disposed in confronting relation to the spring is preferably provided with an arcuate configuration as best seen in FIG. 2, so as to provide somewhat of a cradle" for the spring member 38 in its coaction between the carrier 16 and trigger 20.

Aforementioned ledge portion 36 of trigger 20 also preferably includes inverted slot 60 which receives therein the upper end of post on the carrier for aiding in guiding the pre-travel movement of the trigger relative to the carrier.

Spring 38 possesses such resistance to compression that it will compress fully prior to any compression of the aforementioned spring 18 urging the carrier to its off position.

Accordingly, it will be understood that upon squeezing of the trigger 20 by the finger of the operator, the initial trigger pre-travel" movement acts to first compress spring 38 until surface 46 on front wall of the trigger (FIG. 3) engages the frontal end surface on carrier 16 (FIG. 5), whereupon the carrier will thereafter be moved by a further trigger actuation to the right as viewed in FIG. 1 to cause actuation of the electrical switch contacts in housing 14 in the manner fully described in the referenced patent structures. Such pretravel movement of the trigger 20 relative to the carrier 16 thereby requires the operator to first move the trigger through a predetermined magnitude ofpre-travcl" prior to the actuation of the carrier which in turn then actuates the control or switch device.

Phantom line position A (FIG. 1) illustrates the pretravel movement of the trigger 20 relative to the carrier so that when the trigger arrives at position A, surface 46 on frontal wall 40 of the trigger is in engagement with the abutment surface 50 on the carrier 16, and thereafter continued squeezing of the trigger will cause movement of the carrier relative to the control housing 14 to cause actuation of the control. Phantom line position B illustrates the maximum movement of the trigger and carrier relative to the housing to define the full on" position of the control.

A second embodiment of control of the present invention is illustrated in FIG. 6. in which structure the trigger 80 is snapped over the free end 81 of the contact carrier 82. More specifically the trigger 80 is formed with a cavity 83 being somewhat T-shaped in section and which opens to the rear edge 84 of the trigger 80.

The free end 81 of the carrier 82 is formed with projections 85 extending outwardly from opposite edges thereof.

In mounting the trigger 80 onto the carrier 82, the free end 8I of said carrier is placed into the opening of the trigger cavity 83 whereby either one of the projections 85 is inside said cavity and behind the forward surface of the rim 87 formed at the mouth of the cavity. The trigger may then be forced over the remaining carrier projection 85, the trigger 80 and carrier 82 being constructed of suitably resilient material to enable said trigger to be mounted on the end of the carrier in the position shown in FIG. 6.

As thus mounted, the trigger 80 may be pressed or moved to the right as shown in FIG. 6 relative to and over the carrier 82, a distance as determined between the front wall 88 of the carrier 82 and the end of boss 89 formed on the front wall of the trigger 80 and ex tending into cavity 83. This trigger pre-travel thus enables the trigger 80 to be moved onto and relative to the carrier prior to any carrier movement. And, when the boss 89 engages the front wall 88 of the carrier, said trigger and carrier thereafter move as a unit to operate the control.

Spring 91 interposed between the boss 89 and the front wall 88 of the carrier normally urge the trigger to the position shown in FIG. 6. Rails 93 formed in said trigger cavity 83 permit the carrier projections to move therealong effective to guide the trigger movement onto the carrier. And, as in the previous embodiment, the spring 91 is intended to be fully compressed prior to any compression of spring I8 which urges the carrier to its fully extended or off position.

From the foregoing description and accompanying drawings it will be seen that the invention provides a novel electrical control or switch for electrically driven tools, power appliances or the like, wherein the trigger is provided with pro-travel movement relative to the contact carrier, which carrier member controls the actuation of the control or switch device.

Terms and expressions which have been used are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of any of the features shown or described, or portions thereof, and it is recognized that various modifications are possible within the scope of the invention claimed.

What is claimed is:

I. In an electrical control comprising, a housing, a carrier mounted for movement relative to the housing for causing actuation of the control, a trigger member adapted to be squeezed by the finger of an operator to cause actuation of the carrier, a longitudinally extending passageway formed in said trigger for receiving one end of the carrier, guide means in said passageway for guiding the movement of the trigger relative to the carrier, means interconnecting said carrier and trigger member to provide predetermined pre-travel movement of the trigger relative to the carrier including.

spring means coacting between the trigger and the carrier for yieldingly resisting movement of the trigger relative to the carrier, abutment means on the trigger and on the carrier adapted for engagement after said predetermined pro-travel of the trigger relative to the carrier effective to cause actuation of the carrier upon further movement of the trigger. and a post on the distal end of said carrier engageable with a pin mounted on said trigger for limiting outward movement of the trigger relative to the carrier.

2. A control as defined in claim I and wherein said trigger includes a ledge portion overlying said carrier, said pin being mounted on said ledge portion and depending therefrom. and said spring means between said trigger and carrier being disposed below said pin and extending in a direction generally transverse to the direction of extension of said pin.

3. A control as defined in claim 2 and including a recess in the distal end of said carrier for receiving said spring means therein. and means on said trigger disposed in alignment with said recess for positioning said spring means with respect to said recess.

4. A tool trigger operated switch for controlling the operation of a portable electric tool wherein the portable tool is provided with a casing or housing in which the switch is mounted. said switch having a housing mounted in the interior of the tool easing, said casing having an opening adjacent to said switch housing. a trigger member extendable through said opening and adapted to be squeezed by the finger of an operator. a

carrier member movably carried in said switch housing for causing actuation of said switch. spring means coacting between the trigger member and the carrier member for yieldingly resisting movement of the trigger member relative to the carrier member and to provide predetermined pre-travel movement of the trigger member relative to the carrier member. and abutment means on the trigger member and the carrier member for engagement after said predetermined pro-travel effective to move the carrier member and cause actuation of the switch.

5. A tool trigger operated switch as defined in claim 4 and wherein means on the carrier member coact with the trigger member to limit outward movement of the trigger member through the opening in the tool hous- 

1. In an electrical control comprising, a housing, a carrier mounted for movement relative to the housing for causing actuation of the control, a trigger member adapted to be squeezed by the finger of an operator to cause actuation of the carrier, a longitudinally extending passageway formed in said trigger for receiving one end of the carrier, guide means in said passageway for guiding the movement of the trigger relative to the carrier, means interconnecting said carrier and trigger member to provide predetermined pre-travel movement of the trigger relative to the carrier including spring means coacting between the trigger and the carrier for yieldingly resisting movement of the trigger relative to the carrier, abutment means on the trigger and on the carrier adapted for engagement after said predetermined pretravel of the trigger relative to the carrier effective to cause actuation of the carrier upon further movement of the trigger, and a post on the distal end of said carrier engageable with a pin mounted on said trigger for limiting outward movement of the trigger relative to the carrier.
 2. A control as defined in claim 1 and wherein said trigger includes a ledge portion overlying said carrier, said pin being mounted on said ledge portion and depending therefrom, and said spring means between said trigger and carrier being disposed below said pin and extending in a direction generally transverse to the direction of extension of said pin.
 3. A control as defined in claim 2 and including a recess in the distal end of said carrier for receiving said spring means therein, and means on said trigger disposed in alignment with said recess for positioning said spring means with respect to said recess.
 4. A tool trigger operated switch for controlling the operation of a portable electric tool wherein the portable tool is provided with a casing or housing in which the switch is mounted, said switch having a housing mounted in the interior of the tool casing, said casing having an opening adjacent to said switch housing, a trigger member extendable through said opening and adapted to be squeezed by the finger of an operator, a carrIer member movably carried in said switch housing for causing actuation of said switch, spring means coacting between the trigger member and the carrier member for yieldingly resisting movement of the trigger member relative to the carrier member and to provide predetermined pre-travel movement of the trigger member relative to the carrier member, and abutment means on the trigger member and the carrier member for engagement after said predetermined pre-travel effective to move the carrier member and cause actuation of the switch.
 5. A tool trigger operated switch as defined in claim 4 and wherein means on the carrier member coact with the trigger member to limit outward movement of the trigger member through the opening in the tool housing. 